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<meta charset="UTF-8">
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<title>demo</title>
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<body>
<h1>let和const命令的用途</h1>
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<script type="text/javascript">
// const map = new Map();
// map.set('first', 'hello');
// map.set('second', 'world');
// for (let [key, value] of map) {
//   console.log(key + " is " + value);
// }
// first is hello
// second is world

function f({x, y, z}) { 
    console.log(x , y , z);
 }
f({z: 3, y: 2, x: 1});

let jsonData = {
  id: 42,
  status: "OK",
  data: [867, 5309]
};
let { id, status, data: number } = jsonData;
console.log(id, status, number);
// 42, "OK", [867, 5309]

</script>

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